Conventional electrical power systems utilize a synchronous electrical generator for generating AC power. Particularly, such a generator may include a rotor and a stator having a stator coil. In applications such as an aircraft, the rotor is driven by an engine so that electrical power is developed in the stator coil.
Aircraft power systems include plural loads to be powered. Such loads may include avionics DC loads, such as electronic systems, pulsating loads, such as radar, and AC loads, such as fans. The generator comprises a DC exciter followed by a rotating rectifier and a synchronous main generator. The AC power developed in the main generator stator coil is rectified to provide DC power on a DC link. This power, which may be on the order of 270 volts DC, can be provided directly to DC loads, through DC--DC converter circuits to DC loads, or through an inverter circuit to an AC bus for powering AC loads.
Pulsating loads generate significant repetitive voltage transients in the power system. Such transients must be effectively controlled by a generator control unit.
For DC bus protection, prior systems typically utilize DC circuit breakers and DC current sensors, such as Hall effect devices, which tend to be more expensive and larger in size and weight than AC circuit breakers and AC current sensors, such as current transformers. In an application such as an aircraft, size and weight criteria are quite important due to limitations therefor.
The present invention is intended to solve one or more of the problems discussed above in a novel and simple manner.